Samenvatting (EN)

Patients with Obsessive Compulsive Disorder (OCD) try to reduce obsessive uncertainty by 'perseverative compulsions', like checking repetitively. Earlier studies have found that compulsive perseveration paradoxically enhances uncertainty. This helps to explain why OCD persists. Here, we will examine paradoxical effects of perseveration in the development of OCD. We will test whether, relative to others, OCD patients are generally inclined to respond to uncertainty by perseveration, whether the same holds true for first-degree relatives of OCD-patients, whether in the natural course of OCD perseveration precedes clinical uncertainty, and whether the development of clinical uncertainty can be prevented by abstaining from perseveration.